Do you know what octane fuel F1 cars use?

Lisa Lilley, 33, is Shell's Technology Manager for Ferrari, attending all the grands prix with the storied Italian F1 team. She has been working for Shell for 12 years, ever since graduating from Sheffield University in England. She then spent five years carrying out fundamental research into combustion chemistry, which she used as the basis for her PhD. She joined the F1 program in 2005 and is now responsible for managing the interaction between Shell and Ferrari, which includes overseeing a lab that is brought to each and every F1 race. Executive Editor Mark Gillies caught up with her at the U.S. Grand Prix at Indianapolis in June.

Q: What are the differences between Shell's Ferrari racing fuel and pump gas?Lilley: The F1 fuel has to be made of the same types of components you would find in pump gas, it's just that the ratios are played around with. All of our fuels are manufactured in Chester, England, where Shell has a big technology center—and next door we have a refinery. All the components come straight from the refinery and are the same component streams as we use in European fuel, which is of a higher quality than you would find in the U.S. American fuel probably wouldn't work very well in an F1 car.

Q: So what octane do you run?Lilley: The classification is from 95 to 102 RON, which might not mean too much to U.S. readers, but you can extrapolate. [That's about 90 to 97 octane in the U.S.]

Q: One assumes you would always run 102 octane, then?Lilley: No, not really. Most people associate octane with power, but some octane has anti-knock properties, preventing pre-ignition. When you have a car revving at over 18,000 rpm, the fuel composition is a little different, so we are not normally on the upper limit for octane. Depending on Ferrari's strategy, if they asked for 102 octane, we would give it to them, but normally we are not there.

Q: Shell actually makes 102 octane racing fuel. Is that any different to F1 fuel?Lilley: I think they are very different, but I don't know exactly; such fuels don't have to follow any real regulations—unlike in F1, where the FIA lays down the fuel specification—so you can play around with them a little bit more freely.

Q: What would happen if you put 110 octane racing fuel into an F1 engine?Lilley: I think any gains would be minimal actually, because the engine is designed differently. Octane is not something we generally optimize on. For us, it's very important to have the volatility profile and the right kind of power components.